CELLULAR COMMUNICATION
Receptor
Molecule allowing a cell to recognize a message and respond to it
Ligand
Molecule that specifically binds to another molecule
Cell Junctions
- Local signaling
- Use gap junctions
- Signals can bypass cell membrane
Direct Contact
- Local signaling
- Requires cell to cell contact
- Signal molecule bound on cell membrane
- Signal molecule on one cell binds to receptor molecule on another cell
Paracrine
- Local signaling
- Cell releases soluble signal molecules into the extracellular space
- Signals diffuse from releasing cell and reach target cell
Synaptic
- Local signaling
- Allows neurons to pass signals to other cells
- Use neurotransmitters as signal molecules
Endocrine
- Long distance signaling
- Signals travel through blood vessels before reaching target cell
- Insulin released by pancreas into bloodstream causes cells all over the body to absorb glucose from the bloodstream